The present invention relates generally to a rotary power coupling for the delivery of rotational mechanical power therethrough and, more particularly, to a rotary coupling comprising means for accommodating certain operational strains imposed upon a power user without substantial reflection of such strains into components and/or assemblies of the power train residing upstream of the coupling. In another aspect, the invention comprises the combination of a planetary gear winch and the coupling of the invention.
Planetary gear winches, particularly those of a type usually employed in consort with boat trailers, recreational motor vehicles and the like, conventionally employ power trains comprising an electric motor prime mover coaxially coupled to a planetary gear train, the output of which gear train is, in turn, coaxially coupled to the winch drum. Thus, under no-load conditions, the principal axes of rotation of the several power train components of such winches are usually aligned along a common axis. The planetary gear train may comprise one or more planetary gear speed reduction stages, the gearing of each such stage comprising a central sun gear through which rotary power is delivered to two or more planet gears enmeshed by and surrounding said sun gear and a "reaction" gear surrounding and enmeshing said planetary gears.
Conventionally, the output of the final planetary gear speed reduction stage of the gear train is relatively rigidly coupled to the winch drum, such as by means of sturdy splined shafts or by use of the winch drum flange as the planet gear carrier of the final planetary gear speed reduction stage. While such relatively rigid coupling of the output of the planetary gear train to the winch drum is normally possessed of the benefits of simplicity and good manufacturing economics, it is nonetheless also possessed of certain serious operational deficiencies. Firstly, it is obvious that operational loads imposed upon the winch drum of such winches are reflected into the planetary gear trains thereof. Certain of such loads can tend to displace the axis of rotation of the winch drum and thereby render it eccentric with respect to the principal axis of rotation of the planetary gear train. Additionally, substantial skewing loads can also be imposed on the winch drum whereby the axis of rotation thereof is angularly displaced relative the the principal axis of rotation of the planetary gear train. In either instance, of course, those drum loads which disrupt the coaxial alignment of the axes of rotation of the drum and the planetary gear train can often result in the imposition of deleterious and even destructive unbalanced and/or racking loads upon the gearing of said gear problem has been vastly reduced.
It is a principal object of the present invention to provide a novel rotary power coupling.
It is another object of the invention to provide a rotary power coupling for coupling a source of rotary mechanical power to a power user, said source and said user having essentially common axes of rotation and which coupling can accommodate limited eccentric and/or angular displacements of the axis of rotation of said user relative to that of said source.
It is another object of the present invention to provide a novel planetary gear winch.
It is yet another object of the present invention to provide a planetary gear winch the planetary gear train of which is effectively isolated from deleterious unbalanced and/or racking loads originating by reason of certain operational loads imposed upon the winch drum.
Other objects and advantages of the present invention will in part be obvious and will in part appear hereinafter.